Traditional outdoor heating devices such as campfires may be dangerous to operate as they are usually not self contained. Campfires also generally require an ample amount of solid fuel such as firewood to generate and provide sufficient heat for warmth and/or cooking due to the low burn efficiency of a campfire. More particularly, if the firewood is packed too closely together, insufficient air will be available for complete combustion, causing loss of heat energy, and if the firewood is spaced too far apart, sufficiently high temperatures may be difficult to obtain and maintain because too much air will cool the fire and reduce its efficiency. Furthermore, the ability to build and maintain a campfire also requires considerable skill and effort. For example, to effectively build a campfire, one must be able to identify and gather appropriate kindling material and dry firewood, build a pyramid-like structure over the kindling material using smaller sticks, successfully start burning the kindling material and smaller sticks, and add increasingly larger sticks and firewood as the fire grows in strength while leaving enough space between them for the fire to breathe.
Other outdoor heating devices such as various conventional cook stoves that use a solid fuel source, including but not limited to charcoal burning barbecue and hibachi type stoves, provide a self contained portable heat source as well as a means for cooking. However, because charcoal burns with a low rate of heat output, such prior art heating devices require a substantial amount of fuel to generate the desired amount of heat. Typically, a voluminous amount of charcoal briquettes is stacked upon each other, reducing the available surface area and airflow required for an efficient burn. Furthermore, because charcoal burns at a low rate of combustion, which means that a charcoal bed will burn a long time, such prior art heating devices fail to provide a convenient means of extinguishing the fire without necessitating dumping of the charcoals or waiting for the charcoals to burn out on their own.
Applicant is aware of U.S. Pat. No. 3,765,397 to Henderson which provides a portable and nestable stove having two housings defining a first chamber and a larger second chamber, respectively, each of the housings having a tapered wall configuration extending between a larger open end and smaller open end. A grate, a rack, and one or more draft openings are provided in each housing with the smaller ends of each housing being of like size and configuration for mating with one another. Charcoal or other suitable solid fuel can be placed into either housing which functions as a firebox or heat generating chamber. The entire stove structure is demountable and nestable for ease of storage and transportation.
Applicant is also aware of U.S. Pat. No. 4,909,235 to Boetcker which provides a cooking stove having a semi-conical outer housing and an inverted semi-conical firebox inserted therein. The firebox has a set of openings in its periphery towards the bottom portion thereof which is covered by a ring having similar openings which can be rotated to allow air to flow into the firebox or to prevent the flow of air into the firebox. The housing also has openings which allow air to flow into the area between the housing and the firebox. The interior of the firebox contains a fuel rack upon which fuel such as charcoal briquettes or the like may be placed and ignited. The fuel may be extinguished with the use of a snuffer plate placed into the firebox where the snuffer plate rim rests adjacent to the inside of the firebox in an airtight manner. The ring may then be rotated until the openings on the ring are misaligned with the openings of the firebox to prevent the flow or air into the firebox.
Applicant is further aware of U.S. Pat. No. 5,094,223 to Gonzalea which provides a wood burning portable fire pit grill apparatus having a fire bowl base, a cylindrical wood receiving chamber defined by expanded metal walls above the fire bowl, a pair of separately controlled gas rings encircling the chamber adjacent its side wall at its bottom and middle, a propane gas tank releasably connected to the apparatus and gas rings via a flexible hose and manual quick release coupling. Wood pieces are stacked vertically into the chamber and thus inside the gas rings which, in use, project their flames horizontally toward the stacked wood pieces to advance their burning toward the hot coals state at which time the propane gas and hose may be disconnected and moved away. A removable cooking grill is atop the chamber for use in cooking off the hot coals fire which is achieved in less time than otherwise would be required in a conventional wood fire.
The problem with existing outdoor heating devices is that none of such devices provide a fuel efficient device that is self-extinguishable and collapsible for ease of transport. Therefore, an unaddressed need for an improved outdoor heating device exists to overcome the inadequacies and deficiencies in the prior art.